B1025

Circuit Description
When you first turn the ignition switch to the RUN position, the Inflatable Restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within the SDM. Upon passing these tests the following circuits are measured to ensure that they are within their respective normal voltage ranges:
^ IGNITION 1
^ 23 VLR
^ Deployment loop voltages

The SDM monitors the voltages at DRIVER SIDE LOW terminal 3 and PASSENGER SIDE LOW terminal 4 to detect shorts-to-B+ in the inflator module circuits.

Conditions for Setting the DTC
^ The voltage at PASSENGER SIDE LOW terminal 4 is less than 4.8 volts.
^ The voltage at DRIVER SIDE LOW terminal 3 is more than 4.8 volts for 500 milliseconds.

The CONTINUOUS MONITORING test inspects for this DTC. This test occurs when IGNITION 1 is within the normal operating voltage range.

Action Taken When the DTC Sets
^ The SDM sets a diagnostic trouble code.
^ The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC
^ Current DTC-The voltage at DRIVER SIDE LOW terminal 3 is less than 4.8 volts for 500 milliseconds.
^ History DTC
- You issue a scan tool CLEAR CODES command
- After 250 malfunction free ignition cycles have occurred

Diagnostic Aids
A short to B+ in the Inflatable Restraint Steering Wheel Module circuit may cause an intermittent condition. Inspect circuit 347 and circuit 348 carefully for cut or chafed wires. The diagnostic table directs the technician to note the entry value of DRIVER SENSELO. Comparing the value of DRIVER SENSELO may be helpful in determining if an intermittent condition exists.
When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616-A Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents. When a wire, connector or terminal repair is requested, use the J 38125-B Terminal Repair Kit and refer to Wiring Repairs.

Test Description
The numbers below refer to the step numbers on the diagnostic table:
2. This test determines the driver side low voltage which is measured by the Inflatable Restraint Sensing and Diagnostic Module (SDM).
3. This test isolates the malfunction to one side of the Inflatable Restraint Steering Wheel Module Coil yellow 2-way connector.
4. This test determines whether the malfunction is due to the Inflatable Restraint Steering Wheel Module or the module coil.
7. This test determines whether the malfunction is in circuit 347.
9. This test determines whether the malfunction is in circuit 348.